In caring for patients in a hospital, such as those requiring intensive care, it is desired to provide continuous observations of one or more life functions of each patient; however, the common technique of providing such observation by trained nurses not only requires a large number of nurses but also actually falls short of continuous uninterrupted observation. It is therefore desired to provide a system for accomplishing the continuous observation of multiple patients by means of instrumentation and a single attendant who need not be highly trained.
Patient monitoring systems of various types have been proposed in the prior art. For the most part, these prior art systems may be characterized as telemetering systems wherein the patients or persons being monitored are fitted with one or more sensors which produce signals corresponding to a selected vital function of the person. The signals representing the vital function as detected by the sensors are then transmitted as data signals to a central processing station where the significance of the signals relative to the given patient is determined manually or by a data processing system. Patient monitoring systems of this type are described in the following U.S. Pat. Nos. Vogelman et al 3,572,316, Pacela et al 3,608,542, Buxton et al 3,646,606, and Greatbatch 3,639,907. The difficulty with these prior art systems is that they are very complex, especially at the central station in that they require computer or data processing equipment of relatively large capacity. Additionally, such prior art systems need a fairly sophisticated communication system between the patient monitoring stations and the central station. Because of the complexity and high cost, patient monitoring systems have not been used extensively and there remains a great need in providing multiple patient intensive care without exorbitant costs associated with presently known techniques.